1 Ganglia-groups of neuron cell bodies that lie peripheral to the central nervous system in vertebrates. 2  Bipolar neurons-cell body located near the middle of the axon; characteristic of retinal neurons. 3  Unipolar neurons-cell body lies off to one side of axon; characteristic of sensory neurons.
The principal host for diamonds are rocks formed in the earth's mantle that are known as eclogite and peridotite that are carried to the earth's surface in magmas known as kimberlit e and lamproite.
Diamonds are formed as an allotrope of the element carbon, at depths greater than 90 miles. The pressure and heat at this depth was critical to the formation of the diamonds that are mined at the surface today. At crustal pressures, the stable form of carbon is the allotrope graphite.